In electric arc furnaces, scrap iron is melted in a shell, which usually comprises a bottom and a side wall.
The shell is also provided with a cooling system, for example based on water circulation, but as a rule cooling is applied only to the side wall, because it would be difficult and even dangerous, on account of wear, to install a water circulation system inside the bottom.
Furthermore, after the iron scrap has been melted, the molten metal must be poured into a pouring ladle, and pouring is generally effected by slightly inclining the shell about a tipping axis. For this purpose the furnace shell is placed on a floor raised relative to the workshop floor on which ladle handling trucks circulate. The shell support floor is mounted for tilting about a horizontal axis, under the action of a jack, for example. Thus, once a ladle has been brought on its handling truck to a point near the shell, in the pouring position, pouring can be effected by slightly inclining the support floor and the shell by means of jacks.
The refractory lining is subject to considerable wear and must be periodically repaired or replaced. It has now been found that it would be helpful to be able to act directly on the bottom, which is more liable to wear than the side wall. Moreover, even when the repair is restricted to the bottom, this operation is very lengthy and requires a shutdown of the furnace and, in certain cases, of the entire steel works.
U.S. Pat. No. 3,952,140 discloses an electric arc furnace comprising a shell consisting of a plurality of sections, particularly a bottom and a side wall, these two parts being covered with a refractory lining.
Means for removing the different parts of the furnace, for the purpose of facilitating the replacement of the refractory lining, are placed above the plant, and this entails the removal of the side wall before the bottom can be reached.